MCAT and melanoma: As such, transcription-activator-like effector (TALE)-DddA-derived cytosine base editor (DdCBE) G1397/G1333 candidates bearing nuclear export signals targeting m.12,436G>A and m.11,944G>A sites in Mt-Nd5 were synthesized and screened in mouse B78-D14 amelanotic melanoma cells (B.16 derivative, Cdkn2a−/−)9 to identify efficient pairs (Fig. 1a–d).